III Nitride semiconductor devices, specifically GaN based switching devices, are well known. Such devices are normally depletion mode devices in which a normally conducting electron gas or 2Deg layer is formed, for example, between a GaN layer and an AlGaN layer atop the GaN layer. A gate structure atop the AlGaN layer is operable to interrupt the normally conducting 2Deg layer to turn off the normally conducting 2Deg or electron gas layer.
It would be very desirable to employ the characteristics of III Nitride devices in a normally off enhancement mode FET or in a power device with a plurality of enhancement mode and depletion mode devices.